Question 1

Which of the following best describes the motility mechanism of spirochetes such as Treponema pallidum?

Accepted Answer

Flexing and rotation driven by endoflagella located in the periplasmic space

Question 2

A patient presents with a painless lesion on the genitals that heals spontaneously, followed by a generalized rash on the palms and soles weeks later. Which stage of syphilis is most likely responsible for the rash?

Accepted Answer

Secondary syphilis

Question 3

Which diagnostic method is most appropriate for confirming a case of secondary syphilis?

Accepted Answer

Serological tests such as VDRL or FTA-ABS

Question 4

Treponema pallidum can cross the placenta and infect the fetus, leading to which of the following characteristic symptoms in congenital syphilis?

Accepted Answer

Hutchinson's teeth (notched, barrel-shaped)

Question 5

Borrelia hermsii causes relapsing fever due to which immunological phenomenon?

Accepted Answer

Antigenic variation of surface proteins

Question 6

Which of the following is the primary vector for transmission of Borrelia burgdorferi, the causative agent of Lyme disease?

Accepted Answer

Ticks

Question 7

A patient develops a bull's eye rash, fever, and joint pain after hiking in a wooded area. What is the most likely diagnosis?

Accepted Answer

Lyme disease

Question 8

Which of the following best explains the pathogenesis of cholera toxin in Vibrio cholerae infection?

Accepted Answer

Toxin activates adenyl cyclase, increasing cAMP and causing secretion of Cl$$^-$$, HCO$$_3^-$$, Na$$^+$$, K$$^+$$, and H$$_2O $$into the intestinal lumen

Question 9

Which of the following is the main symptom of cholera infection?

Accepted Answer

Watery diarrhea

Question 10

Campylobacter jejuni is a common cause of bacterial gastroenteritis. Which of the following is a key virulence factor?

Accepted Answer

Heat-labile enterotoxin (CJT)

Question 11

Helicobacter pylori contributes to peptic ulcer formation by producing which enzyme?

Accepted Answer

Urease

Question 12

Which of the following bacteria is an obligate intracellular parasite and alternates between elementary and reticulate bodies?

Accepted Answer

Chlamydia trachomatis

Question 13

A biofilm found on the tooth surface that is made of multiple species is called:

Accepted Answer

Plaque

Question 14

Which of the following is a major complication of untreated tertiary syphilis?

Accepted Answer

Gummas (painful swollen tumors)

Question 15

Which of the following is the most common rickettsial infection in the United States and is transmitted by ticks?

Accepted Answer

Rocky Mountain spotted fever

Question 16

Which of the following bacteria lacks a cell wall and is highly pleomorphic, causing atypical pneumonia?

Accepted Answer

Mycoplasma pneumoniae

Question 17

A veterinarian is investigating an outbreak of abortions in sheep and cattle. Which bacterial species is most likely responsible?

Accepted Answer

Campylobacter fetus

Question 18

Which of the following is the preferred treatment for early Lyme disease?

Accepted Answer

Doxycycline or amoxicillin

Question 19

Which of the following best describes the role of biofilm in dental caries formation?

Accepted Answer

Biofilm harbors bacteria that ferment sugars, producing acids that dissolve enamel

Question 20

Which of the following equations best represents the conversion catalyzed by Helicobacter pylori's urease enzyme?

Accepted Answer

$$ \mathrm{Urea} + \mathrm{H}_2\mathrm{O} \rightarrow 2\mathrm{NH}_3 + \mathrm{CO}_2 $$

Miscellaneous Bacterial Agents of Disease: Study Notes (Chapter 21, Talaro's Foundations in Microbiology)

Study Guide - Practice Questions

Study Guide - Flashcards